A. STUDIES ON THE IL-1-MEDIATED DISEASES, NOMID AND DIRA: 1. We have completed long-term follow up of 42 patients with NOMID and MWS/NOMID overlap who have been treated for over ten years in long-term follow or who were started on treatment early in life. The evaluation of the data are ongoing and will provide valuable insights it the long-term outcome of NOMID patients treated with IL-1 blocking agents including the prevention of organ damage, and the long-term safety of chronic IL-1 blockade in NOMID patients. 2. We have collected long-term outcome data on DIRA patients treated with anakinra and are in the process of summarizing these data. 3. We identified novel mutations causing the monogenic osteomyelitis syndrome, Majeed syndrome, and are completing studies on the impact of the mutation on osteoclast activation and differentiation. B. ASSESSMENT OF GENTIC CAUSE AND BENEFIT AND SAFETY OF TYPE I IFN BLOCKADE IN TYPE I IFN-MEDIATED AIDs THAT CLINICALLY MIMIC CANDLE, AND SAVI. 1. SAVI and CANDLE/PRAAS are genetically-defined rare autoinflammatory interferonopathies that are caused by gain-of-function mutations in TMEM173 encoding STING and genes encoding proteasome components or proteasome assembly genes (PSMB8, PSMB4, PSMA3, PSMB9 and POMP). We have identified that JAK inhibition with the small molecule baricitinib improved manifestations in patients with CANDLE and SAVI with 50% of CANDLE patients achieving inflammatory remission off corticosteroids (9,12). We have identified novel CANDLE-causing mutations (3) and validated our findings on the clinical efficacy of JAK inhibitors in additional CANDLE patients (2, 3, 15) and patients with the autoinflammatory interferonopathy AGS (5). 2. We characterized novel autoinflammatory diseases that are clinical mimics of CANDLE. Their pathogenic pathways in these conditions are not only due to increased IFN signaling, but also due to increased NF-kB signaling in the peripheral blood. C. IDENTIFY AND CHARACTERIZE THE GENETIC CAUSE OF CONDITIONS THAT CAUSE CHRONICALLY ELEVATED IL-18 LEVELS. The identification of gain-of-function mutations in the innate immune sensor, NLRC4 (2014) represents the first monogenic defect that may link high IL-18 levels and macrophage activation syndrome (1). 1. Collaborating with the Canna lab, which tested this association in hyperferritinemic and autoinflammatory patients, we found a high correlation of MAS risk with chronic (sometimes lifelong) elevation of mature IL-18, particularly with IL-18 unbound by IL-18 Binding Protein, or free IL-18. This paper confirms a unique connection between MAS risk and chronic IL-18, which distinguishes thes syndromes from the familial hemophagocytic lymphohistiocytosis diseases (fHLH) that converge with MAS in the activation of hyperferritinemic inflammation and complements the cytotoxic impairment which is the cause of fHLH in driving the cytokine storm that escalates hyperferritinemic inflammation to the end-organ damage that ensues with a high mortality in these syndromes (14). 2. We also identified a novel mutation in CDC42 that causes a high IL-18 state that in the context of stress and infections leads to MAS and thus increase the number of genetic conditions caused by high IL-18 states beyond NLRC4 (7). We have identified a novel not yet genetically characterized disease that presents with high IL-18 serum levels and with pulmonary alveolar proteinosis and predisposition to the development of MAS. D. CLINICAL AND GENETIC EVALUATION OF PATIENTS WITH NOT YET CHARACTERIZED EARLY-ONSET AUTOINFLAMMATORY DISEASES Our findings of genetic defects that cause autoinflammatory disease manifestations revealed mutations in genes that lead to the IFN- mediated conditions (SAVI and CANDLE) and our biomarker and treatment data suggest a role of IFN overproduction in driving autoinflammatory/ autoimmune disease phenotypes. We continue to evaluate and treat patients with severe inflammatory diseases that present early in infancy particularly those with interferonopathies but yet unknown genetic mutations All patients undergo a detailed immune evaluation that includes assessment of their assessed their IFN response gene signature, genetic analyses using next generation sequencing, (whole exome sequencing (WES) and/or whole genome sequencing (WGS)). We are in the process of characterizing novel interferon-mediated diseases with partial responses to JAK inhibition. E. DEVELOPMENT AND VALIDATION OF BIOMARKERS AND FOCUS ON UNDERSTANDING MONOCYTE AND MACROPHAGE DIFFERENTIATION TO IMPROVE DIAGNOSIS AND MONITORING OF AUTOINFLMAMMTORY DISEASES. 1. We screened 65 patients with undifferentiated autoinflammatory diseases using the IFN score and serum cytokine analyses and identified novel diseases. We identified 3 conditions that present with an elevated IFN signature and with high NFKB signaling in peripheral blood cells, the latter distinguishing them from CANDLE and SAVI. 2. We identified peripheral blood monocytes as the source for IFNB1 in SAVI but not in CANDLE patients and establish differences in the sources of IFN between the different autoinflammatory interferonopathies. F. USE OF IN VITRO CELL CULTURE SYSTEMS TO MODEL ORGAN-SPECIFIC IMMUNE DYSREGULATION AND ORGAN DAMAGE IN SELECTED AUTOINFLAMMATORY DISEASES. 1. The severity of interstitial lung disease varies in patients with SAVI from being absent to being severe. Complications from interstitial lung disease are the major cause of childhood mortality in SAVI. We assessed chest computed tomography (CT) and pulmonary function tests (PFTs) and lung tissue where available in 12 SAVI patients and found a genetic modifying region to be associated with the severity of lung disease. We identified genetic markers of disease severity that causes SAVI. CONCLUSIONS AND SIGNIFICANCE Our program provides an integrative approach to the clinical, genetic and immunologic evaluation of patients with autoinflammatory diseases that continues to provide insights into the disease pathogenesis and into the use of targeted therapeutics to better treat patients and improve disease outcomes. Our studies have resulted in the discovery of novel autoinflammatory diseases that provided insights into the disease pathogenesis and revealed targets for treatment. 1. We expanded the genetics of CANDLE by identifying mutations in PSMG2 a novel monogenic cause of CANDLE. 2. In an ongoing compassionate use study using the JAK1/2 inhibitor baricitinib that inhibits IFN signaling we showed clinical benefit and collected safety data in patients with CANDLE and SAVI and in patients with clinical and laboratory evidence of IFN mediated disease. In a pharmacokinetic/dynamic study, we assessed the pharmacokinetic profile in children and young adults and provided a dosing regimen for patients with autoinflammatory interferonopathies. 3. The identification of mutations in NLRC4 that cause macrophage activation syndrome led to the exploration of the role of IL-18 in macrophage activation and to the characterization of 2 novel diseases associated with high IL-18 levels, one caused by mutations in CDC42 and a complex disease IL-18 PAP-MAS that presents with highly elevated serum IL-18 levels, pulmonary alveolar proteinosis (PAP) and predisposition to MAS. We contributed to biomarker studies in patients who present with macrophage activation syndrome in the context of various other autoinflammatory diseases.